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190+ questions

JavaScript questionsTypeScript supported

190+ JavaScript and TypeScript interview questions, from implementing common library APIs, utility functions, algorithms, to building UI components and more.

Try these popular JavaScript questions

Array.prototype.concatImplement the Array.prototype.concat() method
Languages
JSTS
Array.prototype.filterImplement the Array.prototype.filter() method
Languages
JSTS
Coding Format
Number of questions
34 questions
Total time
14 hours total

Questions List

  • CounterWarm Up QuestionBuild a simple counter that increments whenever a button is clicked
    Difficulty
    Easy
    Available frameworks
    Users completed
    8315 completed
  • Mortgage CalculatorBuild a calculator that computes the monthly mortgage for a loan
    Difficulty
    Easy
    Available frameworks
    Users completed
    699 completed
  • TabsBuild a tabs component that displays a list of tab elements and one associated panel of content at a time
    Difficulty
    Medium
    Available frameworks
    Users completed
    1203 completed
  • Todo ListBuild a Todo list that lets users add new tasks and delete existing tasks
    Difficulty
    Medium
    Available frameworks
    Users completed
    2109 completed
  • Traffic LightBuild a traffic light where the lights switch from green to yellow to red after predetermined intervals and loop indefinitely
    Difficulty
    Medium
    Available frameworks
    Users completed
    657 completed
  • Digital ClockBuild a 7-segment digital clock that shows the current time
    Difficulty
    Medium
    Available frameworks
    Users completed
    408 completed
  • Job BoardBuild a job board that displays the latest job postings from Hacker News
    Difficulty
    Medium
    Available frameworks
    Users completed
    436 completed
  • AccordionBuild an accordion component that a displays a list of vertically stacked sections with each containing a title and content snippet
    Difficulty
    Easy
    Available frameworks
    Users completed
    1111 completed
  • Flight BookerBuild a component that books a flight for specified dates
    Difficulty
    Easy
    Available frameworks
    Users completed
    517 completed
  • Generate TableGenerate a table of numbers given the rows and columns
    Difficulty
    Easy
    Available frameworks
    Users completed
    560 completed
  • Progress BarBuild a progress bar component that shows the percentage completion of an operation
    Difficulty
    Easy
    Available frameworks
    Users completed
    1009 completed
  • Progress BarsBuild a list of progress bars that fill up gradually when they are added to the page
    Difficulty
    Easy
    Available frameworks
    Users completed
    535 completed
  • Temperature ConverterBuild a temperature converter widget that converts temperature values between Celsius and Fahrenheit
    Difficulty
    Easy
    Available frameworks
    Users completed
    864 completed
  • Accordion IIBuild an accessible accordion component that has the right ARIA roles, states, and properties
    Difficulty
    Medium
    Available frameworks
    Users completed
    232 completed
  • Accordion IIIBuild a fully accessible accordion component that has keyboard support according to ARIA specifications
    Difficulty
    Medium
    Available frameworks
    Users completed
    114 completed
  • Analog ClockBuild an analog clock where the hands update and move like a real clock
    Difficulty
    Medium
    Available frameworks
    Users completed
    181 completed
  • Grid LightsBuild a grid of lights where the lights deactivate in the reverse order they were activated
    Difficulty
    Medium
    Available frameworks
    Users completed
    268 completed
  • Like ButtonBuild a Like button that changes appearance based on the states
    Difficulty
    Medium
    Available frameworks
    Users completed
    341 completed
  • Progress Bars IIBuild a list of progress bars that fill up gradually in sequence, one at a time
    Difficulty
    Medium
    Available frameworks
    Users completed
    180 completed
  • Star RatingBuild a star rating component that shows a row of star icons for users to select the number of filled stars corresponding to the rating
    Difficulty
    Medium
    Available frameworks
    Users completed
    733 completed
  • Tabs IIBuild a semi-accessible tabs component that has the right ARIA roles, states, and properties
    Difficulty
    Medium
    Available frameworks
    Users completed
    113 completed
  • Tabs IIIBuild a fully accessible tabs component that has keyboard support according to ARIA specifications
    Difficulty
    Medium
    Available frameworks
    Users completed
    69 completed
  • Progress Bars IIIBuild a list of progress bars that fill up gradually concurrently, up to a limit of 3
    Difficulty
    Medium
    Available frameworks
    Users completed
    112 completed
  • Tic-tac-toeBuild a tic-tac-toe game that is playable by two players
    Difficulty
    Medium
    Available frameworks
    Users completed
    151 completed
  • Signup FormBuild a signup form that does validation on user details and submits to a back end API
    Difficulty
    Medium
    Available frameworks
    Users completed
    272 completed
  • StopwatchBuild a stopwatch widget that can measure how much time has passed
    Difficulty
    Medium
    Available frameworks
    Users completed
    137 completed
  • Transfer ListBuild a component that allows transferring of items between two lists
    Difficulty
    Medium
    Available frameworks
    Users completed
    141 completed
  • Undoable CounterBuild a counter with a history of the values and ability to undo/redo actions
    Difficulty
    Medium
    Available frameworks
    Users completed
    119 completed
  • Whack-A-MoleBuild a popular arcade game where players attempt to hit moles as they pop up from holes in a board
    Difficulty
    Medium
    Available frameworks
    Users completed
    54 completed
  • Memory GameBuild a memory game where the player needs to match pairs of cards
    Difficulty
    Medium
    Available frameworks
    Users completed
    57 completed
  • Progress Bars IVBuild a list of progress bars that fill up gradually concurrently, up to a limit of 3 and allows for pausing and resuming
    Difficulty
    Hard
    Available frameworks
    Users completed
    62 completed
  • Tic-tac-toe IIBuild an N x N tic-tac-toe game that requires M consecutive marks to win
    Difficulty
    Hard
    Available frameworks
    Users completed
    38 completed
  • Transfer List IIBuild a component that allows transferring of items between two lists, bulk selection/unselection of items, and adding of new items
    Difficulty
    Hard
    Available frameworks
    Users completed
    40 completed
  • WordleBuild Wordle, the word-guessing game that took the world by storm
    Difficulty
    Hard
    Available frameworks
    Users completed
    27 completed